Thermoplastic polyurethane-elastomers from cyclohexane-1,4-diisocyanate

Abstract

Thermoplastically workable polyurethane-elastomers are disclosed which are obtained through polyaddition of substantially pure trans-cyclohexane-1,4-diisocyanate, macrodiols of average molecular weight from 800 to 4000 and bisethoxylated Bisphenol A or mixtures thereof with short-chain diols customarily employed as chain lengtheners. The polyurethanes possess the advantage that their softening points lie in a very favorable temperature range which makes possible their thermoplastic workability at below the decomposition temperature, and also guarantees outstanding mechanical-elastic characteristics as well as excellent long-term light stability. As a result the polyurethanes according to the present invention are outstandingly suitable as material for shaped bodies to be employed in areas of use placing high requirements on the employed materials. For example, highly valuable elastomer fibers can be manufactured from these polyurethanes by means of melt spinning.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims: 
     
       1. Thermoplastically workable polyurethane-elastomers, obtained by polyaddition of substantially pure trans-cyclohexane-1,4-diisocyanate, marcrodiols of an average molecular weight from 800 to 4000 and chain lengtheners having at least two active hydrogen atoms, said chain lengtheners composed of bisethoxylated Bisphenol A or mixtures of bisethoxylated Bisphenol A with other short-chain diols customarily employed as chain lengtheners. 
     
     
       2. Thermoplastically workable polyurethane-elastomers according to claim 1, wherein said macrodiols are composed from a copolyesterdiol. 
     
     
       3. Thermoplastically workable polyurethane-elastomers according to claim 2, wherein said copolyesterdiol is formed from adipic acid, neopentylglycol and 1,6-hexanediol. 
     
     
       4. Thermoplastically workable polyurethane-elastomers according to claim 1, wherein said macrodiols are selected from the group consisting of polyesters, polyacetals, polylactones and polycarbonates. 
     
     
       5. Thermoplastically workable polyurethane-elastomers according to claim 1, wherein said macrodiols are composed of polyesters based upon adipic acid and glycols. 
     
     
       6. Thermoplastically workable polyurethane-elastomers according to claim 5, wherein said polyester is a mixed polyester of adipic acid and several glycols. 
     
     
       7. Thermoplastically workable polyurethane-elastomers according to claim 5, wherein said glycols are short-chained, having from 2 up to 6 carbon atoms. 
     
     
       8. Thermoplastically workable polyurethane-elastomers according to claim 5, wherein said glycols are long-chained, having at least 6 chain carbon atoms. 
     
     
       9. Thermoplastically workable polyurethane-elastomers according to claim 1, wherein said macrodiols are blended with tri-functional compounds containing triols as alcohol component. 
     
     
       10. Thermoplastically workable polyurethane-elastomers according to claim 9, wherein said trifunctional compounds are polyesters and contain trimethylolpropane as alcohol component. 
     
     
       11. Thermoplastically workable polyurethane-elastomers according to claim 1, obtained through polyaddition of cyclohexane-1,4-diisocyanate-isomer mixtures containing at least an 85% portion of trans-isomers of cyclohexane-1,4-diisocyanate. 
     
     
       12. Thermoplastically workable polyurethane-elastomers according to claim 1, obtained through polyaddition of cyclohexane-1,4-diixocyanate-isomer mixtures containing at least a 95% portion of trans-isomers of cyclohexane-1,4-diisocyanate. 
     
     
       13. Thermoplastically workable polyurethane-elastomers according to claim 1, obtained through polyaddition of cyclohexane-1,4-diisocyanate-isomer mixtures containing at least a 99% poriton of trans-isomers of cyclohexane-1,4-diisocyanate. 
     
     
       14. Thermoplastically workable polyurethane-elastomers according to claim 1, wherein said chain lengthener is composed of mixtures of bisethoxylated Bisphenol A with other short-chain diols customarily employed as chain lengetheners, said mixtures containing bisethoxylated Bisphenol A to the extent of at least 40 Mol percent. 
     
     
       15. Thermoplastically workable polyurethane-elastomers according to claim 1, wherein said chain lengthener is composed of mixtures of bisethoxylated Bisphenol A with other short-chain diols customarily employed as chain lengtheners, said short-chain diols being selected from the group consisting of ethyleneglycol, 1,4-butanediol, 2,3-butanediol, 2,5-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,2-propanediol, 1,3-propanediol, and 1,5-pentanediol. 
     
     
       16. Thermoplastically workable polyurethane-elastomers according to claim 1, wherein said chain lengethener mixture of bisethoxylated Bisphenol A with other short-chain diols contains butane-1,4-diol as short-chain diol. 
     
     
       17. Process for the production of thermoplastically workable polyurethane-elastomers comprising polyadding substantially pure trans-cyclohexane-1,4-diisocyanate, macrodiols of an average molecular weight from 800 to 4000 and chain lengetheners with at least two active hydrogen atoms, the chain lengetheners being composed from bisethoxylated Bisphenol A or mixtures of bisethoxylated Bisphenol A with other short-chain diols customarily employed as chain lengtheners. 
     
     
       18. Process for the production of polyurethane-elastomers according to claim 17, wherein said macrodiol is a copolyesterdiol. 
     
     
       19. Process for the production of polyurethane-elastomers according to claim 18, wherein said copolyester diol employed is formed from adipic acid, neopentylglycol and 1,6-hexanediol. 
     
     
       20. Process for the production of polyurethane-elastomers according to claim 17, employing as cyclohexane-1,4-diisocyanate a cyclohexane-1,4-diisocyanate-isomer mixture having a trans-isomers portion amounting to at least 85%. 
     
     
       21. Process for the production of polyurethane-elastomers according to claim 17, employing as cyclohexane-1,4-diisocyanate a cyclohexane-1,4-diisocyanate-isomer mixture having a trans-isomers portion amounting to at least 95%. 
     
     
       22. Process for the production of polyurethane-elastomers according to claim 17, employing as cyclohexane-1,4-diisocyanate a cyclohexane-1,4-diisocyanate-isomer mixture having a trans-isomers portion amounting to at least 99%. 
     
     
       23. Process for the production of polyurethane-elastomers according to claim 17, employing a mixture of bisethoxylated Bisphenol A and short-chain diols, said mixture containing bisethoxylated Bisphenol A to the extent of at least 40 Mol percent. 
     
     
       24. Process for the production of polyurethane-elastomers according to claim 17, employing as chain lengthener a mixture of bisethoxylated Bisphenol A and short-chain diol, said short-chain diol being butane-1,4-diol. 
     
     
       25. In a process for thermoplastic working-up of materials into elastic shaped bodies, the improvement wherein polyurethane according to claim 1 is employed as said material. 
     
     
       26. In a process for the production of elastomer fibers of the type in which a material is melted and spun into fibers, the improvement wherein polyurethanes according to claim 1 are employed as said material.